The invention relates to a method of making a hybrid wood product that includes a void-free contact surface.
The depletion of old-growth forests, coupled with an increasing demand for wood-based building materials, has pushed the lumber industry to seek more efficient methods to use available wood resources. To minimize the requirement for larger, older trees and to create optimal use of all available wood, wood-products manufacturers have developed composite wood products that fuse smaller pieces of wood. These products lessen the requirement for single-component, solid sawn lumber, and rely on smaller pieces of wood, wood scraps, or lumber processing by-products. For example, particle board is created by cementing small wood chips or fragments together into a composite, whereas fibre board relies on randomly oriented individual wood fibers, which are glued together.
One of the most effective load bearing composites is laminated veneer lumber, or LVL. LVL is produced from thin sheets of wood, which are affixed face to face to create a multi-layered wood product with a common grain orientation. Relatively short pieces of wood can be finger-jointed at their ends to create an elongate, quite strong, composite wood product capable of withstanding significant forces exerted orthogonal to the main axis. Since LVL is multi-layered, localized flaws and weak points in individual layers are distributed randomly. Therefore, LVL has significant structural advantages over a solid sawn, single-component piece of lumber in which structural weaknesses are more likely to be locally distributed across the entire width.
Despite the improved structural properties of LVL and its efficient use of smaller trees, LVL produces a surface inferior to single-component lumber when milled to create a framing component of a structure. The junction between individual layers of LVL, and the layers themselves often include imperfections or voids in any surface created as a result of lamination or from further shaping of the LVL product, such as during milling. These voids disrupt the uniformity of the LVL surface and destroy the ability of LVL to provide a tight, efficient contact junction for joining with another complementary surface, such as contributed by a pane of glass. This tight junction is important to minimize airflow and water leakage through the window frame. Therefore, LVL and other composite wood products are generally unsatisfactory components of a window frame relative to solid sawn lumber.
An object of the invention is to produce a hybrid wood product that maintains the benefits of using composite wood but includes a void-free surface contributed by solid sawn lumber.
A further object of the invention is to provide a method for producing a hybrid wood product with a void-free surface.
The invention provides a hybrid wood product with a void-free surface. The invention further provides a method of making a hybrid wood product with a void-free surface. The hybrid wood product is constructed in several steps. First, a hybrid wood material is produced by laminating a solid sawn lumber key in aligned furrows created in composite wood products. Then this hybrid wood material is cut through both the key and surrounding composite wood layers to create two or more segments that can be further milled or otherwise shaped. The resulting hybrid wood products include a void-free abutment surface formed by a residual portion of the key.